-1
votes
2answers
367 views

Performance of numerical optimization with triple integral [closed]

I'm trying to solve a numerical optimisation that looks something like this: ...
1
vote
3answers
173 views

How can I threshold for a minimum value with MatrixPlot?

Looking at the Options for MatrixPlot, there doesn't seem to be a mechanism for lowerbound threshold - i.e. ignoring values that ...
5
votes
3answers
283 views

How to fix Ticks in Gauges?

Ticks is an option for Gauges. I fail, however, to apply custom Ticks to Gauges. For instance, compare these two: ...
2
votes
2answers
262 views

Simplifying expression to evaluate limit as $y\rightarrow 0$

I often end up with a function that contains the term $1/(1 + x^2/y^2)$, and I need to evaluate this in the limit $y\rightarrow 0$. By hand, I can rewrite this as $y^2/(y^2 + x^2)$, but how can I tell ...
0
votes
2answers
204 views

Can I speed up the following plotting code?

I have the following Mathematica code. I do get the output graphs, but it takes like 12 seconds, on my computer. Longer still if I increase the value of n1. Are ...
2
votes
2answers
212 views

Error when compiling function containing InterpolationFunction

I'm trying to solve a coupled ODE system using NDSolve. The coupling can turn on and off in some regions, and when the coupling is off, the solution can be written ...
5
votes
2answers
830 views

Numerical Integration as Model for Nonlinear Fit

I'm trying to do a fit for parameters of a function within an integral but I'm getting errors when I try and run it. Essentially I want the following fit to work out: ...
42
votes
1answer
1k views

What's inside InterpolatingFunction[{{1., 4.}}, <>]?

I'm curious what's inside the InterpolationFunction object? For example: ...
5
votes
1answer
256 views

Error messages from compiling the Piecewise function

The following works Compile[{{x, _Real}}, Piecewise[{{{0., 0.}, x > 5.}}, {1., 1.}]] but if I enter the Piecewise[...] in ...
0
votes
0answers
64 views
0
votes
1answer
107 views

Random variation inside NMaximize

I am using NMaximize as following code. ...
7
votes
1answer
484 views

StreamPlot with interpolating functions

While working my way through the Wolfram Blog post on simulating fluid flow I started playing with StreamPlot because I preferred quick and ugly visualizations over ...
6
votes
1answer
955 views

Eigenvector corresponding to a specific eigenvalue already found earlier

just a quick question that is very simple but somewhat hard to explain. I am using 4 specific eigenvalues of a large 80x80 k-dependant matrix. I found the 4 eigenvalues of interest for various k and ...
33
votes
6answers
1k views

Creating cross-version compatible documentation with Workbench

Wolfram Workbench allows you to create documentation for your own packages that is similar to the build-in documentation center. Integrating this type of documentation with the documentation center is ...
2
votes
1answer
104 views

Possible to Solve a LocationEquivalenceTest?

I have 5 groups, each containing around 20 elements. These elements are all dependent on x. For example: Set1 = {1.5x + 1, 2x + 0.5, 1 x + 1, ...} etc. Now, I want ...
4
votes
1answer
150 views

Generalization of a rule to N arguments

I am trying to apply a series expansion on a function x[t1,t2,...tn], with an expansion parameter a. For ...
3
votes
2answers
641 views

Speed of convergence for NIntegrate

I'm trying to optimise numerically a function that entails computing the expected value of a truncated trivariate normal distribution and this is taking extremely long -I also get warned about ...
7
votes
1answer
211 views

Saving a source file adds (* ::Package:: *) to the first line

I am running Mathematica 9 on a linux machine and I've encountered the following behaviour that I am trying to understand. When I'm editing multiple source (.m) files using mathematica saving adds a ...
6
votes
1answer
169 views

Graph rendering not working as expected

I'm running the older Mathematica v6 which seems to go through the edges of graphs twice. Is this a bug? Is it fixed on the latest version? Please just try this command: ...
1
vote
0answers
90 views

Using Dynamic to import the chronologically newest file in a directory [duplicate]

Imagine that I have a device continually and sequentially saving files to a specified directory on a Windows machine (such as [E:\ExampleDir]). Call this device a camera with some proprietary drivers ...
3
votes
1answer
403 views

How to change the start path of SystemDialogInput

It seems that every time the start directory of SystemDialogInput is always the same, is it possible to set the start directory to the last used directory? For ...
9
votes
1answer
652 views

Complex valued 2+1D nonlinear PDE using NDSolve

I am trying to follow the main ideas presented in this question, applying it to my own problem, which is a complex, time-dependent, nonlinear PDE: $$i \frac{\partial \psi}{\partial t} = \left[ ...
3
votes
1answer
162 views

Disable and Enable Hyperlinks Graphics

I have a Graphics element which I edit with Drawing Tools. I have determined a technique using NotebookWrite to add ...
1
vote
0answers
74 views

Efficiently generating 3D histograms for large sets 2D coordinates [duplicate]

I'm attempting to generate a 3D histogram for a large set of two-dimensional coordinates ($\approx 10^7$). the x- and y-components of each coordinate are rounded to the nearest integer, and these ...
12
votes
1answer
380 views

solve ODE with divergencies

The solutions of the second order differential equation $$\frac{1}{\eta}\frac{d}{d\eta}\left(\eta \frac{df}{d\eta}\right)+\left(1-\frac{s^2}{\eta^2}\right)f-f^3=0$$ is shown in Fig. 5.2 below, for ...
1
vote
2answers
443 views

Add keyboard shortcut to the DisplayFormula style

Is there a way to set up key bindings for the DisplayFormula and DisplayFormulaNumberedstyles? I am using Mathematica 9 on mac ...
0
votes
2answers
305 views

Unwrapping a list when invoking a function [duplicate]

The minimal working example of my problem is as follows: l = {1, 2, 3, 4} f[a_, b_, c_, d_] = a + b + c + d Now, I'd like to evaluate ...
1
vote
2answers
812 views

Integration and Parallel Computing in Mathematica

In mathematica, how would I use parallel computing (or paralleltable) to compute the integrals of $x^2$, $x$, $3x$ from $x=0$ to $10$ just like in the first answer of ...
4
votes
1answer
304 views

The limit of a product to infinity

What is the difficulty with this question to Mathematica? Is it just a problem with Mathematica v.8.0 or all versions are in trouble with it? Or is something wrong with my input? ...
11
votes
1answer
434 views

How can I set id attribute of elements when I export an SVG file?

Suppose I have a Mathematica graphic such as g = Graphics[{Disk[{-1, 0}, 1/2], Rectangle[]}] I would like to be able to export this graphic from Mathematica ...
6
votes
0answers
549 views

Remote Kernel - Error = MLECONNECT

Configuring a remote kernel with the Kernel Configuration Basic Options I manage to have a new kernel in the list of the kernel that I can open. However when I start the new kernel I get asked for the ...
4
votes
1answer
244 views

Check if an inequality holds among the solutions returned by Solve [duplicate]

Let's say I solve a system: Solve[{a == 3* c, b == 2 *a}, {a, b}] and then want to see if the values found for a and ...
11
votes
3answers
1k views

Can't load LevelScheme package

I am trying to use Mark Caprio's LevelScheme package for customizing graphics, but I haven't been able to get Mathematica to load the package using Get or ...
9
votes
3answers
394 views

PlotMarkers don't change colour for different lines

I have a set of data and several function operating on the same data, that I wish to plot together in a ListPlot. I need different ...
1
vote
2answers
328 views

Clear labelling gray-scale plots

I am plotting a number of functions (at least 4 in one plot) with a legend. Needless to say, it is important that it is clear from the legend which line belongs to which function. I tried to play ...
2
votes
0answers
68 views

Are FEM methods integrated in NDSolve yet? [duplicate]

About a year ago there was a discussion on these forums as to whether FEM methods have already been integrated into NDSolve in Mathematica. The answer back then was ...
3
votes
1answer
190 views

Mouse click on BarChart elements

What I would like to do is explore a data set by clicking on elements in a BarChart. I have some existing code which uses a manipulate which I was hoping to modify. ...
1
vote
1answer
164 views

FindMinimum gives wrong solutions inside a loop

I have a density function $\rho(r,z)$ and I want to calculate the minimum distance $d_{min} = \sqrt{r^2 + z^2}$ from the center (0,0) in which $\rho$ becomes negative. The easiest way is to find where ...
5
votes
1answer
459 views

Erfi[z] expansion in Mathematica: is this a bug?

Looking at the expansion: Series[Erfi[x], {x, Infinity, 1}] I obtain -I+E^x^2 (1/(Sqrt[\[Pi]] x)+O[1/x]^2) (note the ...
2
votes
2answers
300 views

Lossless TIFF or PNG export

I'd like to export an output from MatrixPlot[], however, the output file size seems to depend on my specification of the ImageSize -> {..., ...}. How might I export a TIFF with all of the data in the ...
3
votes
0answers
363 views

Use of RegionFunction with Graphics3D?

I'd like to plot in 3D a long list of polygons created with TetGenConvexHull, but only in regions specified by a function. Is that possible? As I have it my ...
1
vote
1answer
86 views

Make the linked images show well?

Cell[TextData[{ "(16) ", ButtonBox["[images]", BaseStyle->"Hyperlink", ButtonData->{"http://i.stack.imgur.com/gHWby.png", None}]}], "Text"] After click ...
0
votes
2answers
215 views

Taking averages at certain intervals

I am trying to take averages of a large two dimensional array at certain intervals. For example, for the first row, I want to take K averages of 500 values. Here is what I am trying ...
6
votes
2answers
324 views

Add arrows over matrix

How can I plot this graph g1 = Table[x[i, j], {i, 5}, {j, 5}] // Grid; Rasterize@g1 I added these arrows by Ctrl+D's graphics tool. This way maybe hard ...
12
votes
3answers
588 views

Multiple notebooks in Mathematica

While working with multiple files in Mathematica, is there a way to have the names of the files appear along with the minimized window of the file. I mean that sometimes I forget which file was places ...
3
votes
0answers
145 views

DownValues for Built-in Functions

N.B. I have bitten the bullet, and I am going through Leonid Shifrin's "Mathematica Programming: An Advanced Introduction." (Which needs no introduction in this forum) One question I have: could one ...
5
votes
4answers
408 views

Drawing normals to a curve

I want to draw a series of normals to a curve, where the curve has been parametrized by a single angle, i.e., the polar angle. The curve is actually sinusoidal perturbation of a circle of radius ...
-5
votes
1answer
573 views

Solving Det[matrix] == 0 with an 8 x 8 matrix [closed]

I want to solve the equation Det[matrix] == 0 which came from the consistency of solutions of a set of 8 equations. This matrix has two constants λ and μ and two variables $P$ and $q$. I want to get ...
0
votes
1answer
380 views

Function to marginalize a table over given parameters

Let us say I have generated a table tab with entries {p1,..,pd,chi2[p1,..,pd]} of dimension ...
7
votes
2answers
559 views

Memory efficient generation and selection of tuples

The short of this question: I need to find a bunch of n-tuples of {0,1} which do not fail to satisfy a set of (non-linear polynomial) equations, without hogging up all of my memory by trying to ...

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